Power control systems regulate voltages that are often used to provide power to devices, systems, and sub-systems of a variety of electronic systems. FIG. 1 is a schematic diagram of a conventional power control system 100. The power control system 100 includes a pulse-width-modulation (PWM) controller 110 operably coupled with one or more switching converters 120 to operate as a switching regulator. As shown in FIG. 1, the switching converter 120 may include one or more circuit elements to regulate a voltage and generate an output voltage (VOUT) 105. For example, the top right switching converter 120 is shown to include a plurality of transistors (M1, M2) operably coupled with a diode (D1), an inductor (L1) and a capacitor (Cout) in a buck configuration. The other switching converters 120 of the plurality may include circuit elements that are similarly configured, and which are shown to have similar designations. For simplicity, the operation of the PWM controllers 110 will be described only with respect to the top right switching converter 120; however, the other switching converters 120 may have a similar operation.
The PWM controller 110 includes a power control module 112 and a timing control module 114 that are conventionally co-located together. “Co-location” of the power control module 112 and the timing control module 114 means that the power control module 112 and the timing control module 114 are physically located on the same semiconductor die and/or within the same package. For example, the power control module 112 and the timing control module 114 may be formed on different semiconductor dice, yet still may be defined as being co-located if housed within the same package. As a result, at least some of the interconnections between the power control module 112 and the timing control module 114 may be internal connections within the package.
The power control module 112 may be configured to perform the voltage regulation loop function of the power control system 100. For example, the PWM controller 110 may have a pin (labeled as pin “5”) that receives an output voltage 105 of the power control system 100 as a feedback signal. The PWM controller 110 may include another pin (labeled as pin “6”) that receives a ground voltage 106. The voltage difference between the output voltage 105 and the ground voltage 106 is understood by the PWM controller 110 to be the regulated voltage coupled to a load (not shown). The output voltage 105 and the ground voltage 106 may be input into the PWM controller 110 to a unity-gain differential amplifier (not shown) configured for remote sensing of the positive and negative load terminals. The output (DIFFOUT) from the internal differential amplifier may be an output voltage feedback signal that is output from pin “7” to a voltage divider. From the voltage divider, a portion of the DIFFOUT signal may be input into pin “8” of the PWM controller 110. The input signal (EAIN) through pin 8 may be input to an internal comparator (not shown) of the PWM controller 110 for comparison to an internal reference voltage.
The result of the comparison of the EAIN signal and the internal reference voltage may be transmitted to the timing control module 114, which is configured to determine the duty cycle timing for the switching converter 120. In particular, the PWM controller 110 generates timing signals (PWM signals) that are output from the PWM controller 110 through pins “33” and “27.” The timing signals drive the gates of transistors (M1, M2) at the proper duty cycle to regulate the output voltage 105 to the desired voltage. The PWM controller 110 may further include current sense feedback signals (S1+, S1−) that monitor the current flowing through the inductor (L1) to further control the output current. These current sense feedback signals may be input to the timing control module 114 such that the timing control module 114 generates the timing signals to have a duty cycle based largely on the result of the comparison of the EAIN signal and the internal reference signal, as well as the current sense feedback signals.